1. Field of the Invention
This invention relates generally to the fields of molecular biology and more specifically to the effect of adenovirus E1A on tumor cells.
2. Background Information
Both radiation and chemotherapy have significantly contributed to the treatment of cancer. However, impediments to successful therapy by either form of treatment still remain. For example, some tumor types fail to respond to either radiation or chemotherapy. In other instances, originally responsive malignant cells may experience a relapse and become resistant to treatment.
There is evidence that the expression of certain proteins, such as various oncogenes, can increase the susceptibility of cells to apoptosis, also known as programmed cell death. Further, there is evidence that some of these proteins may also confer susceptibility to apoptosis induced by anticancer agents. However, relatively few studies have been done to observe these effects on human tumor cells and there have been no reports on the effect of adenovirus E1A on the sensitivity of human tumor cells and the response of these E1A-expressing cells to chemotherapeutic agents or irradiation.
Given the shortcomings of current chemotherapy and irradiation, namely lack of response and resistance or tolerance to chemotherapy agents, there is a need for developing additional forms of treatment which can enhance a response to chemotherapy or irradiation.
The present invention satisfies these needs and provides related advantages as well. The present invention provides novel methods for treating a tumor cell and enhancing a patient""s response to irradiation and chemotherapy.
The present invention is directed to methods of sensitizing a human tumor cell with adenovirus E1A. The methods involve treating a human tumor cell by, first, introducing into the tumor cell nucleic acid encoding a polypeptide having adenovirus E1A activity, expressing the E1A active polypeptide in the cell, and then either contacting the E1A expressing tumor cell with a chemotherapeutic agent or irradiating the E1A-expressing tumor cell.
The invention also provides methods of enhancing a subject""s response to chemotherapy or irradiation by introducing into a subject""s tumor cells nucleic acid encoding a polypeptide having adenovirus E1A activity, expressing the E1A active polypeptide in the cells and finally, administering either a chemotherapeutic agent or irradiation. This invention also provides a method of treating cancer.